A Microstrip bandpass filter using asymmetrical stepped-impedance resonators

This research proposes a new microstrip bandpass filter using asymmetrical SIRs, resulting to size reduction. This filter structure consists of two open loop resonator which each resonator is difference in size of capacitive loads. This filter has been designed at the operating frequency about 1.8 GHz, bandwidth of 90 MHz. The filter is not only sized reduction, but also low passband insertion loss and high return loss. The full-wave simulator IE3D has been employed to design the slow-wave open-loop resonator.